The PSIC provides communication between research institutions, zoos, and domestic breeding colonies for the sharing of nonhuman primates and tissues and for the exchange of equipment and services. Program activities include referrals by telephone, letter, e-mail and fax, and twice-monthly publication of New Listings, which lists available and wanted primates, tissues, cadavers, equipment, and services. Long-term programs are published every other month in a separate bulletin, Continuing Listings, which serves as a resource guide for researchers. A supplemental publication, the Annual Resource Guide, includes listings from commercial primate suppliers, equipment, transportation companies, and other non-research institution subscribers. At the end of 1998, the PSIC had 479 subscribers and participants. The PSIC database, maintained on an IBM-compatible PC, includes >600 active listings for animals, tissues, suppliers, services, equipment, and other primate resources. In 1998, > 600 referral requests were received and the PSIC was able to provide an average of five sources per request. In all, 3,694 animals were placed, with 379 facilities and >475 researchers, veterinarians, and colony/zoo managers participating in the network. In addition, 55 requests for tissue were satisfied, representing 1,935 specimens acquired, sent, or shared. These numbers do not reflect the actual number of animals or tissues placed directly between institutions as a result of advertisements or notices in PSIC bulletins. The PSIC maintains a website (www.rprc.washington.edu/psic/), which includes information about the program, subscription forms, taxonomy, and links to other websites that answer questions concerning regulations, laws, and primate trade. The PSIC serves a vital conservation function by providing a network for sharing and exchanging nonhuman primate resources between institutions. FUNDING NIH grants RR00166 and RR01240.